im the same as you mate... im fairly fair (that dont sound right lol) but im getting a bit of colour through the sunbeds now..
its all dependent on strength as to how long you want to go on for but as an indication - mine has 100watt tubes and i started at 5 mins and built up from there.. spent a week at 5, then up to 6 and so on... actually have a bit of colour to me now
hth